Sections

Outlook Conditional CSS

Windows Outlook 2003 and above use Microsoft Word as a rendering engine, which can lead to some weird rendering issues. Outlook conditional comments allow us to add bits of HTML that are only read by the Word-based versions of Outlook.

Basic Syntax

We can use MSO (Microsoft Office) tags to add HTML / CSS anywhere in an email template. This code will be ignored by other email clients. Here’s what it looks like:

Ghost Tables

The main way we use MSO tags in our emails is to create “ghost tables” so hybrid emails don’t fall apart in Outlook. Hybrid design uses inline-block, max-width, min-width to stack table columns. Outlook doesn’t support these CSS properties, so we use MSO tags to create “ghost tables” that apply a fixed width just for Outlook.

Targeting Specific Outlook Versions

We usually target all versions of Outlook using <!--[if mso]>. But sometimes when testing emails in Litmus, an email looks ok in one Outlook version but is broken in another. It’s not common but it happens, and there are a few ways to target specific versions of Outlook while omitting others.

Outlook Versions

Using Microsoft Office version numbers allows you to target a specific Outlook version.

Outlook Version(s)

Code

All Windows OutlookMost common

<!--[if mso]> your code <![endif]-->

Outlook 2000

<!--[if mso 9]> your code <![endif]-->

Outlook 2002

<!--[if mso 10]> your code <![endif]-->

Outlook 2003

<!--[if mso 11]> your code <![endif]-->

Outlook 2007

<!--[if mso 12]> your code <![endif]-->

Outlook 2010

<!--[if mso 14]> your code <![endif]-->

Outlook 2013

<!--[if mso 15]> your code <![endif]-->

Outlook 2016

<!--[if mso 16]> your code <![endif]-->

Conditional Logic

Using operators allows you to create conditional expressions for targeting multiple Outlook versions.

Note: We tend to keep our designs simple and don’t use these very often. They’re here if you need them every once in a while, but if you find yourself reaching for these often, please open an issue or ask us about it.